Dr. Ahmed Fathalla Ibrahim
Associate Professor of Anatomy
College of Medicine
King Saud University
E-mail: ahmedfathala@hotmail.com
Dr. Sanaa Al-Sahaarawy
Associate Professor of Anatomy
OBJECTIVES
At the end of the lecture, students should:
List the nuclei related to trigeminal and facial
nerves in the brain stem.
Describe the type and site of each nucleus.
Describe the site of emergence and course of
trigeminal and facial nerves.
Describe the sensory distribution of trigeminal
nerve in the face.
Describe the motor distribution of facial nerve in
the face.
Describe the main motor & sensory effects in
case of lesion of trigeminal and facial nerves.
‫ اوال‬: TRIGEMINAL NERVE ( 5th )
Type: Mixed.
Fibers:
1. General somatic afferent ‫دائما تعني االحساس العام‬:
carrying general sensations from face.
2. Special visceral efferent: ‫هذه الفايبرز تطلق على‬
branchial arch‫اي فايبرز تغذي العضالت الناشئه من‬
‫وهذا االرش هو عباره عن تراكيب جنينيه تتطور لتعطي عضالت‬
‫الوجه والرقبه – اضافه غير مطلوبه‬
supplying muscles originating from 1st branchial
arch.
‫تذكر‬
Spicial somatic afferent
Mean the vision and hearing sences only
Which are the 2nd and 8th nerve
‫‪TRIGEMINAL NERVE NUCLEI‬‬
‫‪Sensation‬‬
‫‪Ganglion‬‬
‫تفصل الحقا‬
‫امتداد لـ‬
‫‪Substintia gletnosia‬‬
‫الحظ ان‬
‫الموتور‬
‫اكثر‬
‫‪Medialy‬‬
‫حسب‬
‫القاعدة‬
‫التي سبق‬
‫شرحها‬
‫في‬
‫الدروس‬
‫االولى‬
TRIGEMINAL NERVE NUCLEI
TRIGEMINAL NERVE NUCLEI
 General somatic afferent:
1. Mesencephalic (pons & midbrain): receives proprioceptive
fibers from face.
2. Principal (main) sensory (pons): receives touch fibers from
face.
3. Spinal (pons, medulla & upper 2-3 cervical segments of spinal
cord): receives pain & temperature sensations from face.
 Special visceral efferent:
• Motor nucleus (pons): supplies:
1. Muscles of mastication (temporalis, masseter, medial &
lateral pterygoid).
2. Anterior ‫ فقط‬belly of digastric ‫الن االنتيريور والبوستيريور ينشئان من‬
‫ & ارتش مختلفه‬mylohyoid muscles.
3. Tensor tympani & tensor palati.
TRIGEMINAL GANGLION
Site: Occupies a
depression in the middle
cranial fossa.
Importance: Contains
cell bodies:
1. Whose dendrites carry
general sensations from
face.
2. Whose axons form the
sensory root of
trigeminal nerve.
‫تعتبر‬
Sensation ganglion
‫مهمه‬
TRIGEMINAL NERVE
 Emerge from middle of
ventral surface of pons.
 Divides into 3 divisions
(dendrites of trigeminal
ganglion):
1. Ophthalmic.( sensory )
2. Maxillary.( sensory )
3. Mandibular. ( the only
mixed division )
 Axons of cells of motor
nucleus join mandibular
division. ( the only mixed
division ) ‫مهمه جدا جدا‬
OPHTHALMIC (PURE SENSORY)
Divides into: frontal, lacrimal & nasociliary branches
passing through superior orbital fissure to orbit.
1. Frontal: supplies skin of face & scalp.
2. Lacrimal: supplies skin of face & lacrimal gland.
3. Nasociliary: supplies skin of face, nasal cavity &
eyeball.
MAXILLARY (PURE SENSORY)
Supplies:
1. Upper teeth, upper gums & maxillary air sinus:
(posterior, middle & anterior superior alveolar
nerves).
2. Face: (zygomaticofacial & infraorbital nerves).
MANDIBULAR (MIXED)
 SENSORY BRANCHES:
1. Lingual: General sensations of anterior 2/3 of tongue.
2. Inferior alveolar: Lower teeth, lower gums & face.
3. Buccal: Face.
4. Auriculotemporal: auricle, temple, parotid gland & TMJ.
 MOTOR BRANCHES: to muscles of mastication, anterior belly of
digastric, mylohyoid, tensor tympani & tensor palati.
SENSORY SUPPLY OF FACE
 OPHTHALMIC:
1. Supratrochlear of frontal:
forehead + medial part of
upper eyelid.
2. Supraorbital of frontal:
forehead + medial part of
upper eyelid.
3. Palpebral branch of
lacrimal: lateral part of
upper eyelid.
4. Infratrochlear of
nasociliary: upper part of
nose.
5. External nasal of
nasociliary: lower part of
nose.
Great auricular nerve
(C2,3)
SENSORY SUPPLY OF FACE
 MAXILLARY:
1. Infraorbital: divides
into:
a) palpebral for lower
eyelid.
b) nasal for ala of
nose.
c) labial for upper lip.
2. Zygomaticofacial:
upper part of cheek.
Great auricular nerve
(C2,3)
SENSORY SUPPLY OF FACE
 MANDIBULAR:
1. Buccal: lower part of
cheek.
2. Mental of inferior
alveolar: lower lip &
chin.
Q:
But T or F :
The whole face receive its sensory supply
from the trigeminal N
‫الجواب‬
F , because small portion is supplied by
facial N
Great auricular nerve
(C2,3)
TRIGEMINAL NEURALGIA
Inflammatory condition affecting one or
more of the three divisions of trigeminal
nerve.
This condition is characterized by recurring of
episodes of intense stabbing ‫ وخز‬pain,
radiating from angle of jaw along a branch of
trigeminal nerve.
Usually involves maxillary & mandibular
nerves, sparing the ophthalmic division.
‫ثانيا‬: FACIAL NERVE ( 7th )
 Type: Mixed.
 Fibers:
1. Special visceral afferent: ‫اذا شفت هذا النوع من الفايبر فاعرف‬
‫انها تنقل اما حاسة الشم او التذوق في هذا الدرس تحمل التذوق‬
carrying taste sensation from anterior 2/3 of tongue.
2. Special visceral efferent: supplying muscles originating
from 2nd branchial arch.
3. General visceral efferent: ‫ دائما تعني‬parasympathetic
secretory fibers to submandibular, sublingual,
lacrimal, nasal & palatine glands.
9 ‫ التي تتغذى بالعصب رقم‬Parotied ‫تغذي كل الغدد بالوجه‬
‫باستثناء‬
FACIAL NERVE NUCLEI
FACIAL NERVE NUCLEI
 Special visceral afferent: upper part of solitary
nucleus (nucleus solitarius): receives taste
sensation from anterior 2/3 of tongue.
 Special visceral efferent: motor nucleus of
facial nerve: supplies: muscles of facial
expression, posterior ‫ مهمه‬belly of digastric,
stylohyoid, stapedius, occipital belly of
occipitofrontalis.
 General visceral efferent: superior salivatory
nucleus: sends preganglionic parasympathetic
secretory fibers to submandibular, sublingual,
lacrimal, nasal & palatine glands.
COURSE OF FACIAL NERVE
1
F
A
C
I
A
L
CANAL
2
3
To posterior belly of
digastric & stylohyoid
Q:
What are the facial divisions inside
the facial canal :
‫ االحمر‬3 ‫ و‬2 ‫ و‬1 ‫الجواب االرقام‬
‫مهمه جدا جدا‬
(To muscles of
facial expression)
FACIAL NERVE:
COURSE & DISTRIBUTION
Taste
FACIAL NERVE:
COURSE & DISTRIBUTION
COURSE OF FACIAL NERVE
Emerges from cerebellopontine angle as 2
roots:
1. Medial motor root: contains motor fibers.
2. Lateral root (nervus intermedius): contains
taste & parasympathetic fibers.
 Passes through internal auditory meatus to
inner ear where it runs in facial canal.
 Passes through stylomastoid foramen &
enters the parotid gland where it ends.
BRANCHES OF FACIAL NERVE
In facial canal:
1. Greater petrosal nerve: carries preganglionic
parasympathetic fibers to lacrimal, nasal &
palatine glands.
2. Chorda tympani: carries:
a) preganglionic parasympathetic fibers to
submandibular & sublingual glands.
b) taste fibers from anterior 2/3 of tongue.
3. Nerve to stapedius.
N.B.: Geniculate ganglion: contains cell bodies of
neurones carrying taste sensations from anterior
2/3 of tongue. ‫مهمه‬
BRANCHES OF FACIAL NERVE
Just after emergence from stylomastoid
foramen:
1. Posterior auricular: to occipitofrontalis.
2. Muscular branches to posterior belly of
digastric & stylohyoid.
Inside parotid gland: gives 5 terminal
motor branches: temporal, zygomatic,
buccal, mandibular & cervical.
MOTOR SUPPLY OF FACE
BELL’S (FACIAL) PALSY
 Lesion of facial nerve (below sytlomastoid foramen) results
in paralysis of muscles of facial expression.
 It is of the lower motor neuron lesion type (whole face, at
same side of lesion, is affected).
 Distortion of face : sagging of angle of mouth, dribbling of
saliva, loss of facial expressions, loss of chewing, blowing,
sucking, unable to show teeth or close eye.
SUMMARY
Both trigeminal & facial nerves are mixed.
Nuclei of trigeminal nerve are found in
midbrain, pons & medulla. They are of the
general somatic afferent & special visceral
efferent types.
The trigeminal nerve emerges from the pons
and divides into: ophthalmic, maxillary &
mandibular divisions that give sensory supply
to face (with an exception of a small area
over ramus of mandible).
SUMMARY
All motor fibers are included in the mandibular
division & supply muscles of mastication.
Nuclei of facial nerve are found in pons. They
are of the special visceral afferent & efferent
types, as well as general visceral efferent type.
The facial nerve emerges from the
cerebellopontine angle, gives motor fibers to
muscles of facial expression, secretory fibers to
submandibular, sublingual, lacrimal, nasal &
palatine glands & receives taste fibers from
anterior 2/3 of tongue.
QUESTION 1
The facial nerve contains
1. Taste fibers from posterior 1/3 of tongue.
2. Fibers carrying general sensation from face.
3. Motor fibers to buccinator.
4. Motor fibers to levator palpebrae superioris.
QUESTION 2
Lesion of mandibular nerve may result in:
1. Loss of sensation of skin over the nose.
2. Loss of lacrimation.
3. Loss of sensory supply of upper teeth.
4. Loss of general sensations of anterior 2/3 of
tongue.
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